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Big changes are in store at the Goldendale Observatory in Goldendale, Washington. The facility’s telescope, installed in 1973, has already been reconfigured and more improvements are planned. Most of the existing facility, save for the south dome that houses the telescope, will be demolished this winter and replaced with a bigger, more useful observatory that operators hope will be operational in time for the solar eclipse in August.

Troy Carpenter, interpretive specialist at Goldendale Observatory State Park, spoke at a recent Rose City Astronomers meeting about plans for improvements at the observatory. Photo: Greg Scheiderer.

Troy Carpenter, interpretive specialist at the observatory, talked about the plans at the recent meeting of the Rose City Astronomers in Portland. He said that up until recently the telescope and facility had been virtually unchanged since they opened.

The telescope, originally a 24.5-inch classical Cassegrain built by amateur astronomers from Vancouver, Washington, was reconfigured this summer.

“It is still the same telescope, but it has become a Newtonian,” Carpenter said. “The primary reason this was converted from Cassegrain to Newtonian is because, frankly, a classical Cassegrain telescope is totally inappropriate in Goldendale, Washington.”

The original scope, with an effective focal ratio of f/14.5, had a focal length of more than 9,000 millimeters. For telescopes and cameras, that’s extremely long.

“I would even say excessively long because it means the telescope can only operate at very high orders of magnification,” Carpenter said. That was bad, because the telescope couldn’t really look at large, dim objects like the Andromeda galaxy or Orion nebula. Also the scope required good seeing conditions, and while it’s dark and clear in Goldendale, the seeing at the observatory isn’t typically great. On top of that, the secondary mirror was eight inches wide with a ten-inch baffle that blocked too much light, leading to poor contrast at the eyepiece.

“In short, what we had was a horribly over-magnified image with terrible contrast all the time, and as a result this very impressive-looking telescope became kind of infamous, and not so much famous, for being awful,” Carpenter said. “All of these issues contributed to the decision to convert it to a Newtonian.”

That work, and some other adjustments to the telescope, its mount, and adjustability, were completed in September. Back to a more appropriate 3,050-millimeter focal length, Carpenter said views through the telescope are much better now. An improvement yet to come is replacement of the primary mirror, which has deteriorated over 43 years of use. In addition, the mirror is five inches thick, weighs 200 pounds, and takes four hours to reach thermal equilibrium, which is essential to good viewing.

A replacement is being fashioned by a company in Pennsylvania that has done work for NASA. The new mirror, computer designed and fabricated from inexpensive materials, will be the same width but just two inches thick and will weigh only 35 pounds. It will take just 15 minutes to cool to ambient temperature. They hope to have it in Goldendale and installed within the next few months. Its price tag, with a generous educational discount, is $25,000, and while that may sound like a lot, Carpenter noted a similar-sized mirror made of fused quartz might go for ten times as much, a quarter million.

New observatory

“We’re tearing it down so that a much larger facility can be built in its place,” Carpenter said. Everything except the south dome that houses the telescope will go. The new facility will include a large auditorium for classes and lectures that will seat about 150, interpretive exhibit space, and a rooftop observation deck. The total cost of the improvements, which are being made in several phases, is $5 million, which is being covered by capital funds appropriated by the Washington State Legislature. Demolition is set for this winter and they hope to be operational with the new facility in time for the total solar eclipse on August 21, 2017. While Goldendale won’t be within the path of totality as it was for the 1979 eclipse, the Sun will be about 98 percent obscured at the observatory that day, so it will still be something to look at.

One page detailing the planned improvements is above; you can see more of them in the latest newsletter from Friends of Goldendale Observatory.

Light pollution

While it’s pretty dark in Goldendale, many feel that light pollution has increased in town in recent years. Concerned folks this summer held a Gorge Night Sky Symposium to discuss the situation. (See our recap of the event.) Carpenter raised a few eyebrows in the room, mine included, with his take on the issue.

Goldendale Observatory. Everything but the dome on the right will be demolished to make way for improved facilities. Photo: Greg Scheiderer.

“I’m going to surprise you by not being the loudest opponent of the light pollution we have in Goldendale,” he said. He added that he grew up in New York and has lived in Philadelphia, so he knows light pollution.

“I’ve been to places where stars don’t exist,” he said. So while Goldendale has some light pollution, Carpenter noted that they still have great views of lots of faint fuzzies in the dark night sky.

“It’s low on my priority list because it’s a politically charged issue and it makes us very unpopular every time we bring it up,” Carpenter explained. “Our friends group, however, does care very much about light pollution and they do work hard.”

He noted that the town of Goldendale is working on an improved lighting code, and is converting to full cut-off, dimmable LED street light fixtures. Despite some light pollution, Carpenter said it’s still a great place for stargazing.

“You can see the Milky Way from horizon to horizon in Goldendale,” he said, “and that’s a wonderful thing.”

Thanksgiving week is a little light on astronomy events, but there are several club meetings and an interesting talk on the calendar.

Habitability at Proxima b

Victoria Meadows. Photo: UW.

There has been a great deal of talk about exoplanet Proxima b since its discovery in orbit around our nearest stellar neighbor, Proxima Centauri, was announced this summer. The planet’s orbit is within the habitable zone of the star, but there’s still a great deal of question about how habitable planets can actually be when they orbit are close to M dwarf stars such as Proxima Centauri. Victoria Meadows, a professor of astronomy at the University of Washington and principal investigator for the NASA Astrobiology Institute’s Virtual Planetary Laboratory, will talk about how they’re modeling the Proxima system and prospects for observing this interesting exoplanet at 3 p.m. this Tuesday, November 22 during an astrobiology colloquium in Physics/Astronomy Auditorium 118 on the UW campus in Seattle.

Club events

The Rose City Astronomers will hold their monthly meeting at 7:30 p.m. Monday, November 21 at the Oregon Museum of Science and Industry in Portland. The guest speaker will be Troy Carpenter, administrator of the Goldendale Observatory State Park in Washington, who will talk about the limitations of human vision, how those limitations hinder our ability to observe the universe, and the technological solutions of the past century that allow us to transcend these challenges. Carpenter will also talk about the Goldendale Observatory upgrade project.

The Island County Astronomical Society will hold its monthly meeting at 6:30 p.m. Monday, November 21 at the Oak Harbor Library. No information about guest speakers or programming had been published as of this writing.

Ron Hobbs. Photo: Greg Scheiderer.

The Eastside Astronomical Society will meet at 7 p.m. Tuesday, November 22 at the Lake Hills Library in Bellevue. Guest speaker Ron Hobbs, a NASA Solar System Ambassador, will talk about how amateur astronomers and other citizen scientists are contributing to space exploration by helping to process the deluge of imagery that comes down daily from space probes.

Futures file

You can scout out future astronomy events on our calendar. New additions to the calendar this week include: